Boston Scientific’s Promus Element Drug Eluting Stent was approved by FDA in late November and now the agency has elected to require that the company includes a warning on its packaging about the risk of stent shrinkage.

Background

The phenomenon known as stent shrinkage has been in the medical device press recently, initially provoked by an Irish study in which it was suggested that the newer iterations of very fine “thinner wire” stents may be susceptible, potentially leading to catastrophic failure or at very least leaving vulnerable lesions unprotected.

At medlatest we reported recently that FDA had undertaken to investigate the situation more fully and this recent requirement placed on Boston Scientific may be the first tangible evidence of the agency’s involvement. According to an article published on medtech news site MassDevice; “Although there’s been only one reported incident of deformation involving a Promus stent from among more than 4,600 implantations in clinical trials,” according to the federal watchdog agency, “an unspecified number of significant adverse events had been reported.”

Asked about the process Boston Scientific spokeswoman responded by email that; “Boston Scientific generated the labeling language describing longitudinal stent deformation to provide the user with full information on how to deal with this infrequent phenomenon. The language was then agreed upon with FDA.”

Dr. Cindy Grines, editor of theJournal of Interventional Cardiology, cited data from a bench test conducted by Abbott “showing that the Element family of stents (including the Omega and Ion) may shorten up to 46 percent under the force that an interventional cardiologist may exert to advance a post-dilation balloon or intravascular ultrasound device,” calling the results “very disturbing” and perhaps hinting at what FDA may have agreed to on the paclaging, which is likely to advocate caution when inserting these devices.